If sometimes it seems like the two candidates for president are speaking different languages, the reason is simple:

They are.

President Barack Obama and Mitt Romney use distinct vocabularies. Each has a campaign glossary of sorts to define himself, criticize the other guy, highlight opposing economic philosophies.

Fair shot or economic freedom? The nation's welfare or class warfare? You're-on-your-own economics or the heavy hand of government?

The president has tried to cast himself as the champion of the middle class. He claims Romney wants to perpetuate failed economic policies that favor the rich and privileged business interests over everyday workers. Obama regularly denounces tax breaks for millionaires and billionaires and frequently talks about the importance of ``playing by the rules.''

Romney has portrayed himself as Mr. Turnaround, the hands-on guy whose 25 years in the private sector give him the ideal resume to revive an economy he contends has gone from bad to worse under the president. His speeches are filled with patriotic references to the Founding Fathers and regular mentions of ``free enterprise'' and ``prosperity.''

``In a lot of ways, it's the standard party line - Democrat, working-class rhetoric, Republican, business class,'' says Mitchell McKinney, professor of communication at the University of Missouri.

``Both are playing to the base. ... Obama has to address those disparities in the economy without seeming that he is anti-business, anti-capitalist. ... Romney wants to tout the making of money and successful working of the capitalist system but not highlight in any way the downside. In that sense they both have fine lines they're trying to walk.''

Both men have tripped on their own rhetoric.

There was Obama's recent retreat from his assertion that ``the private sector is doing fine'' and Romney's declaration that ``corporations are people.'' In coming months, McKinney says, the candidates, surrogates and big-money political groups will repeat certain words and phrases ``so America comes to accept their narrative as reality. Clearly, words do matter.''

So which ones matter most? Some examples from the still-evolving economic glossary of Campaign `12:

ECONOMIC FREEDOM: Or, government get out of the way. Romney subscribes to a longstanding Republican philosophy that the less government, the better the chances for a flourishing economy. He reiterated his belief in unfettered markets and minimal regulation in a March speech at the University of Chicago. The school's economics department has long been regarded as friendly confines for such thinking. It was home to Milton Friedman, the influential economist and apostle of free-market theory. (Romney began his speech with a Friedman anecdote.)

In ``The Freedom to Dream,'' Romney said ``freedom'' 29 times.

``When he talks about economic freedom and saving the country - the religious is entwined with the economic,'' says David Frank, a University of Oregon professor and expert on presidential rhetoric. ``It's a very powerful message... the government should not intervene in the free market, one ruled by individuals who are successful because of God's grace.''

The message also echoes former President Ronald Reagan, who famously declared that government is the problem, not the solution.

COLLECTIVE AMNESIA: Obama's critique of what he says is a trait shared by Republicans who've championed laissez-faire policies but ignored the results. The president argues they've conveniently forgotten that inadequate regulation, an irresponsible financial sector and a free market that operated without ``rules of the road'' led the nation to the worst economic meltdown since the Great Depression.

The president's pitch: Remember the financial debacle of 2008, the ``broken-down theories'' that helped trigger it and don't forget Romney and other Republicans are offering more of the same.

FAIR SHOT: Also see fair share, fair play and fair. A central campaign theme for Obama. His belief that the government has a role in creating conditions for prosperity, that the growing income gap is hazardous to the nation and the recipe for a stable middle class is to give everyone a fair chance to succeed.

Obama used some form of ``fair'' 15 times in his speech last December in Osawatomie, Kan., reiterating his call for higher taxes for the rich and rejecting trickle-down economics as a dry spigot.

The prairie setting was ripe with personal and political symbolism: Obama's mother and grandparents were from Kansas (good chance to flash his humble roots credentials). Osawatomie also was where Teddy Roosevelt in 1910 unveiled his vision for a New Nationalism, calling for ``practical equality of opportunity for all.'' Obama invoked the former president's name and pointedly noted Roosevelt was branded a radical and a socialist back then - labels that have a familiar ring to Obama today.

``He really wants to hit the equality of opportunity, the fairness argument that has traditionally worked very well for Democrats,'' says John Murphy, a University of Illinois associate professor specializing in presidential rhetoric. ``Think way back to the New Deal, the Fair Deal, those were all slogans based on, `Hey, everybody gets an equal shot.'''

Murphy also says the recent Wall Street protests - where anger over income disparity prompted the rallying cry, ``We are the 99 percent!'' - deserve credit for putting the issue on the radar. ``The Occupy movement has given an opening to Obama to make the arguments that might not have been there,'' he says. ``It helped set the agenda just like the Tea Party did in 2010.''

OPPORTUNITY SOCIETY: A phrase with long Republican lineage now used by Romney to describe a society in which people and businesses succeed based on merit and free enterprise, not government doling out benefits, regardless of effort. Reducing the size of federal government is essential. Reagan spoke of an opportunity society and Newt Gingrich's Conservative Opportunity Society (founded in 1983) preached the importance of moving from a `liberal welfare state' to one centered on opportunity.

ENTITLEMENT OR GOVERNMENT-CENTERED SOCIETY: See above. Romney's criticism of Obama policies, contending the president is transforming America so people rely more on government because the economy does less. Romney synonyms: ``heavy hand of government'' or ``the invisible boot of government,'' which he claims stifle free enterprise, ``one of the greatest forces of good this world has ever known.''

YOU'RE-ON-YOUR-OWN ECONOMICS: Obama's words to describe how he says Republicans respond to Americans unable to fend for themselves. His shorter version: ``Tough luck.'' He says that's the GOP's response to those who need help because they're poor, don't have health insurance or are jobless. Obama calls it a ``cramped narrow conception'' of liberty.

SOCIAL DARWINISM: The label some Democrats have attached to GOP House Budget Committee Chairman Paul Ryan's fiscal austerity plan for a sweeping overhaul of Medicare, deep social service cuts and lower tax rates. Many Republicans, including Romney, have expressed support as a way to curb government spending. Many Democrats say this approach would squeeze the already struggling poor, forcing them to compete for fewer resources while the wealthy would thrive, a cruel economic survival of the fittest. Obama called the plan ``thinly veiled'' Social Darwinism.

CLASS WARFARE: A wide-ranging criticism by Romney and other Republicans of the Occupy Wall Street movement and Obama policies that highlight income inequity, notably the Buffett rule. The proposal is named after billionaire Warren Buffett and calls for everyone earning a $1 million a year or more to pay at least 30 percent of their income in taxes. Buffett himself has complained that he pays a lower tax rate than his secretary.

Romney claims Obama is trying to stoke envy by focusing on the income gap on the campaign trail. Early this year, Romney told a TV interviewer: ``I think it's fine to talk about those things in quiet rooms and discussions about tax policy and the like.''

Obama says asking the rich to sacrifice more to help in tough times is not class warfare, but advancing the nation's welfare.

FOOTNOTE: During the GOP primaries, the ``class warfare'' line was a verbal bludgeon for Republicans to bash one another. Rick Santorum and Gingrich both pilloried Romney with the phrase.

JOB CREATORS: A popular phrase, often appropriated by congressional Republicans (Romney also has used it) to lionize small business owners while opposing plans to raise taxes. At times, repeated with the unanimity of a Greek chorus. A term also criticized by Democrats and others, including Paul Krugman, Nobel Prize-winning economist and New York Times op-ed columnist. He recently wrote that a ``right-wing political correctness'' has rendered it impossible to discuss ideas that challenge ``established order'' so instead of the wealthy ``we're supposed to call them `job creators''' and talking about inequality is deemed ``class warfare.''

Last year, U.S. Sen. Barbara Boxer, a California Democrat, dismissed job creator as ``so much bull.'' Comedian-satirist Jon Stewart mocked it, joking: ``Republicans are no longer allowed to say that people are rich. You have to refer to them as job creator. You have to say that this chocolate cake is so moist and job creator.''

Job creator, according to Frank, the Oregon professor, is a ``linguistic shift that takes the onus off capitalism'' and transforms it into a ``force of good'' - rather than laying off people, businesses are seen as providing opportunities and a paycheck.

While these words are shaping the debate, what isn't said on the campaign trail is equally revealing.

Case in point: Romney recently made several references to former President George W. Bush as Obama's ``predecessor,'' avoiding the name of someone who was very unpopular when he left office. Romney also doesn't identify by name Bain Capital, the private equity company he headed, though he boasts of his business prowess while working there. The president, for his part, doesn't talk about the individual mandate in his health care reform bill.

``You want to avoid nouns that can be used as sound bites that can be turned into something potentially negative,'' says Kathleen Hall Jamieson, an expert on political communication at the University of Pennsylvania's Annenberg Center. Not mentioning the mandate makes sense, she says, because it's unpopular, as does Romney not identifying his company ``because he doesn't want to be tied to everything Bain does.'' She points out during the GOP primaries, Romney's rivals accused Bain of predatory tactics and ``vulture capitalism.''

By fall, McKinney says, it'll become clearer what words and messages resonate with the public.

If voters ``define our ailing economy as an election that needs a president who will protect those struggling against big business and uncaring economic forces, then perhaps it's advantage Obama,'' he says, If they ``think that what we need most during this time of economic uncertainty is a president who understands global financial markets, investment forces and so forth, then perhaps it's advantage Romney. These two candidates are struggling to help voters interpret just what sort of economic savior we need in the White House. ... I think the verdict is still out.''